Maccus mac Arailt

Maccus mac Arailt (died 984 - 987?) or Maccus Haraldsson was a Scandinavian or Norse-Gael king. He and his brother Gofraid were active in the lands around the Irish Sea in the 970s and 980s. Maccus's name is sometimes incorrectly given as Magnus; it is instead a name of Middle Irish origin.

Maccus and Gofraid are usually assumed to be members of the Uí Ímair, a kin group tracing its descent from Ímar (died 873), sometimes identified with the saga-character Ivar the Boneless. Their father Aralt or Harald is usually identified with the Aralt mac Sitric, king of Norse-Gael Limerick, who was killed in Connacht in 940. This identification would make Maccus and Gofraid nephews of Amlaíb Cuarán, the King of Dublin. An alternative proposal, advanced by Benjamin Hudson, makes Gofraid and Maccus sons of a Viking chief named Harald who was active in Normandy, but this has received little support.

The first record of Maccus may be in 971 when the Brut y Tywysogion records an attack on Penmon in Wales, site of an important church, by "Marcus" son of Harald. Welsh annals record an attack on Anglesey two years later by a son of Harald. The Brut y Tywysogion states that it was Maccus's brother Gofraid who led this attack. That same year, 973, Maccus is listed by John of Worcester and William of Malmesbury as one of the kings present in attendance with King Edgar of England at the meeting at Chester. Maccus is called "king of many islands", suggesting that he ruled over the Hebrides, and perhaps also the Isle of Man, although this last is uncertain. Maccus is listed as a witness to a charter of King Edgar which is dated to around this time, S 808, but this is generally thought to be a late forgery.

Maccus may have appeared again in 982, joining Gofraid in an attack on Wales. In 984 the brothers came to Waterford, where they joined up with Brian Bóruma, king of Munster, and with Ivar of Waterford, king of Waterford, their combined armies and fleets attacking Dublin. After this, Maccus disappears from the chronicles.

An unnamed son of Harald won a battle on the Isle of Man in 987, but whether this was Maccus or Gofraid is unclear. No children of Maccus are known.